Setting copy permissions for target data in a copy relationship

1. A computer program product for copying data from a first storage to a second storage, wherein the computer program product comprises a non-transitory computer readable storage medium having computer readable program code embodied therein that executes to cause operations, the operations comprising: performing a first copy operation to copy source data from a first location in the first storage to a first data copy at a second location in the second storage; receiving a request to perform a second copy operation to copy requested data from the first data copy in the second storage to a second data copy, wherein the requested data comprises the first data copy of the first copy operation; determining whether the requested first data copy is in a state that does not permit copying in response to receiving the request; performing the second copy operation to copy the requested first data copy from the second storage to a second data copy in a third location external to the first storage in response to determining that the requested first data copy is not in the state that does not permit the copying; and denying the request in response to determining that the requested first data copy is in the state that does not permit copying.

2. The computer program product of claim 1 , wherein the determining that the requested first data copy is in the state that does not permit copying comprises: determining whether the first data copy provides a valid recovery point for the source data, wherein the requested first data copy is in the state that does not permit copying in response to determining that the first data copy does not provide a valid recovery point.

3. The computer program product of claim 1 , wherein the first copy operation continuously transmits updated data that needs to be copied from the source data in the first storage to the first data copy in the second storage, and wherein the second copy operation comprises a point-in-time copy operation at the second storage.

4. The computer program product of claim 1 , wherein the second copy operation copies the first data copy to the second data copy in a third storage.

5. A computer program product for copying data from a first storage to a second storage, wherein the computer program product comprises a computer readable storage medium having computer readable program code embodied therein that executes to cause operations, the operations comprising: performing a first co operation to copy source data from the first storage to a first data copy in the second storage, wherein the source data and the first data copy are in a consistency session; maintaining a session integrity lock for the consistency session, wherein the session integrity lock is set to indicate that the first data copy in the consistency session is in the state that does not permit copying when the data in the consistency session has entered a non-recoverable state; receiving a request to perform a second copy operation to copy requested data from the first data copy in the second storage to a second data copy, wherein the requested data comprises the first data copy of the first copy operation; determining whether the session integrity lock indicates that the first data copy is in the state that does not permit copying in response to receiving the request; performing the second copy operation to copy the requested first data copy from the second storage to a second data copy in response to determining that the requested first data copy is not in the state that does not permit the copying; and denying the request in response to determining that the requested first data copy is in the state that does not permit copying.

6. The computer program product of claim 5 , wherein the copying of the source data to the first data copy in the consistency session is managed by a first controller managing the first storage and a host coupled to a second controller managing the second storage, and wherein the second copy operation to copy the first data copy to the second data copy is managed by the second controller.

7. The computer program product of claim 5 , wherein the operations further comprise: determining whether a synchronization or resynchronization operation is being performed or has completed for the consistency session; setting the session integrity lock for the consistency session to the state that does not permit copying in response to determining that the synchronization or resynchronization operation is being performed for the consistency session; and setting the session integrity lock for the consistency session to the state that permits copying in response to determining that the synchronization or resynchronization operation being performed for the consistency session has completed.

8. The computer program product of claim 5 , wherein there are a plurality of sessions established between the first and the second storage managed as a master session, wherein there is a master session integrity lock to provide overall consistency across all the sessions in the master session, wherein the determining whether the requested data is in the state that does not permit copying comprises determining whether the master session integrity lock indicates that the target data including the requested data is in the state that does not permit copying.

9. The computer program product of claim 5 , wherein the operations further comprising: maintaining a session copy lock for the session indicating whether copying is permitted for the first data copy in the consistency session; receiving an obtain command with respect to the consistency session; setting the session copy lock to indicate that copying is not permitted for the first data copy in the consistency session in response to receiving the obtain command; receiving a release command with respect to the consistency session; setting the session copy lock to indicate that copying is permitted for the first data copy in the consistency session in response to receiving the release command.

10. The computer program product of claim 9 , wherein the operations further comprise: determining whether the session copy lock for the consistency session indicates that copying is permitted in response to receiving the request, wherein the first data copy is determined to be in the state that does not permit copying in response to determining that the session integrity lock indicates the state that does not permit copying or determining that the session copy lock indicates that copying is not permitted.

11. The computer program product of claim 10 , wherein the obtain and release commands are sent by a user at a user interface, and wherein the first data copy is in the state that does not permit copying in response to determining that the first data copy is not at a valid recovery point, and wherein the session copy lock is capable of preventing the second copy operation when the requested data is at the valid recovery point.

12. A system for copying data from a first storage to a second storage, comprising: a first controller managing the first storage, wherein the first controller executes code to perform a first copy operation to copy source data from a first location in the first storage to a first data copy at a second location in the second storage; a second controller managing the second storage, wherein the second controller executes code to perform operations, the operations comprising: receiving a request to perform a second copy operation to copy requested data from the first data copy in the second storage to a second data copy, wherein the requested data comprises the first data copy of the first copy operation; determining whether the requested first data copy is in a state that does not permit copying in response to receiving the request; performing the second copy operation to copy the requested first data copy from the second storage to a second data copy in a third location external to the first storage in response to determining that the requested first data copy is not in the state that does not permit the copying; and denying the request in response to determining that the requested first data copy is in the state that does not permit copying.

13. The system of claim 12 , wherein the determining that the requested first data copy is in the state that does not permit copying comprises: determining whether the first data copy provides a valid recovery point for the source data, wherein the requested first data copy is in the state that does not permit copying in response to determining that the first data copy does not provide a valid recovery point.

14. The computer program product of claim 12 , wherein the first copy operation continuously transmits updated data that needs to be copied from the source data in the first storage to the first data copy in the second storage, and wherein the second copy operation comprises a point-in-time copy operation at the second storage.

15. A system for copying data from a first storage to a second storage, comprising: a first controller managing the first storage, wherein the first controller executes code to perform a first copy operation to copy source data from the first storage to a first data copy in the second storage, wherein the source data and the first data copy are in a consistency session; a second controller managing the second storage; a host system coupled to the second controller, wherein the host system executes code to maintain a session integrity lock for the consistency session, wherein the session integrity lock is set to indicate that the first data copy in the consistency session is in the state that does not permit copying when the data in the consistency session has entered a non-recoverable state; wherein the second controller executed code to perform operations, the operations comprising: receiving a request to perform a second copy operation to copy requested data from the first data copy in the second storage to a second data copy, wherein the requested data comprises the first data copy of the first copy operation; determining whether the session integrity lock indicates that the first data copy is in the state that does not permit copying; performing the second copy operation to copy the requested first data copy from the second storage to a second data copy in response to determining that the requested first data copy is not in the state that does not permit the copying; and denying the request in response to determining that the requested first data copy is in the state that does not permit copying.

16. The system of claim 15 , wherein the first controller communicates with the host system to perform the copying of the source data to the first data copy in the consistency session.

17. The system of claim 15 , wherein the operations performed by the host system further comprise: determining whether a synchronization or resynchronization operation is being performed or has completed for the consistency session; setting the session integrity lock for the consistency session to the state that does not permit copying in response to determining that the synchronization or resynchronization operation is being performed for the consistency session; and setting the session integrity lock for the consistency session to the state that permits copying in response to determining that the synchronization or resynchronization operation being performed for the consistency session has completed.

18. The computer program product of claim 15 , wherein the operations performed by the host system further comprise: maintaining a session copy lock for the session indicating whether copying is permitted for the first data copy in the consistency session; receiving an obtain command with respect to the consistency session; setting the session copy lock to indicate that copying is not permitted for the first data copy in the consistency session in response to receiving the obtain command; receiving a release command with respect to the consistency session; setting the session copy lock to indicate that copying is permitted for the first data copy in the consistency session in response to receiving the release command.